Farmers are urging the Government to make food security a top priority on the day the country’s cupboards would run bare if households relied only on British food.

Whitehall figures show that self-sufficiency levels have stagnated at around 60 per cent for most of the last two decades, with around three-quarters of the shortfall imported from the rest of the European Union.

In the late-80s and early-90s, self-sufficiency was up to 75 per cent.

The president of the National Farmers’ Union, Minette Batters, said: “The statistics show a concerning long-term decline in the UK’s self-sufficiency in food and there is a lot of potential for this to be reversed.

“And while we recognise the need for importing food which can only be produced in different climates, if we maximise on the food that we can produce well in the UK then that will deliver a whole host of economic, social and environmental benefits to the country.

“The UK farming sector has the potential to be one of the most impacted sectors from a bad Brexit. A free and frictionless free trade deal with the EU and access to a reliable and competent workforce for farm businesses is critical to the future of the sector.

“And as we replace the EU’s common agricultural policy, we must keep a sharp focus on what productive, progressive and profitable farm businesses need from a domestic agricultural policy.”

The impact of the summer heatwave on farmers had pushed concerns around food production into “sharp focus”, the union leader added.

“This has been a real test for Government to show the farmers and the many concerned members of the public that they think that our ability to produce food in this country is truly important.

“We strongly believe that every British citizen should be entitled to a safe, traceable and high-quality supply of British food that is produced to some of the highest animal welfare and environmental standards in the world.

“Home-grown food production must have the unwavering support of Government if we are to achieve this post-Brexit.”

Prime Minister Theresa May has insisted that the public should take “reassurance and comfort” from Government preparations for a no-deal Brexit after ministers suggested food and medicines would be stockpiled in case of shortages.